Electronic motion picture camera

ABSTRACT

The invention relates to an electronic motion picture camera having an optical receiving system and a beam splitter which splits the receiving beam path into a taking beam path leading to an optoelectronic taking sensor and a viewfinder beam path leading to an optical viewfinder. The camera has an electronic display for the reproduction of an additional image. An optical vision mixer is arranged in the viewfinder beam path by which the taken image and the additional image can be directed in the direction of the viewfinder such that the taken image or the additional image, or the taken image and the additional image as a uniform image, can be observed in the viewfinder.

This application claims priority to German Application No. 10 2004 004806.1, filed Jan. 30, 2004.

The invention relates to an electronic motion picture camera having anoptical receiving system and a beam splitter which splits the receivingbeam path into a taking beam path leading to an optoelectronic takingsensor and a viewfinder beam path leading to an optical viewfinder.

With electronic motion picture cameras, the taken wanted signal isusually displayed as a monitor image in an electronic viewfinder or on ascreen attached to the camera. The taken image reproduced in this mannerserves, for example, for the control of the sharpness. An electronicviewfinder has the disadvantage that the environment of the taken imagecannot be observed. Potentially disturbing objects outside the takenimage section can thus not be recognized before they move into the takenimage. Viewfinders which are based on electronic displays are above alllimited with respect to the reproduction quality.

Motion picture cameras are also known which are provided with an opticalviewfinder. With these cameras, some of the light current detected bythe optical receiving system is led into an optical system which isconnected in parallel to the taking sensor and which indicates the sametaken image for the cameraman which is also recorded by the takingsensor. A high image quality of the viewfinder can hereby be achieved.It is, however, disadvantageous that no additional image information canbe made available to the cameraman.

It is thus an object of the invention to provide an electronic motionpicture camera whose viewfinder has a high image quality and which canbe used flexibly for different demands with respect to the reproductionof the taken image and further image information.

This object is satisfied by a motion picture camera having the featuresof claim 1 and in particular in that the camera has an electronicdisplay for the reproduction of an additional image; and in that anoptical vision mixer is arranged in the viewfinder beam path by which ataken image imaged by the optical receiving system and the additionalimage reproduced by the electronic display can be directed in thedirection of the viewfinder such that the taken image, or the additionalimage, or the taken image and the additional image as a uniform image,can be monitored in the viewfinder.

The optical receiving system therefore images the taken image along thetaking beam path on the taking sensor and moreover presents the takenimage in the viewfinder, with the camera in accordance with theinvention having a hybrid viewfinder system with two superimposed beampaths. An optical vision mixer which permits the presentation of thetaken image detected by the optical receiving system and of anadditional image generated by an electronic display is integrated intothe viewfinder beam path of an optical viewfinder, with the taken imageand the additional image being able to be presented to the viewer as asingle, uniform motion picture or still picture in the viewfinder. Thehigh image quality of an optical viewfinder is thereby combined with thepossibility of reflecting additional image information into theviewfinder beam path by means of an electronic display or of introducingit optically in another manner.

Instead of a joint presentation of the taken image and of the additionalimage as a uniform image, optionally only the taken image imaged by theoptical receiving system can also be presented in the viewfinder, forexample prior to the start of the actual recording by means of thetaking sensor. Optionally, only the additional image reproduced by theelectronic display can also be presented in the viewfinder. Thispossibility is particularly advantageous, if the received light shouldbe fully directed to the taking sensor and not in the direction of theviewfinder due to the poor lighting of the taking motif. In this case,the viewfinder can be used as an electronic viewfinder by means of theelectronic display and of the vision mixer.

The additional image can support the cameraman in a variety of mannersduring the take, with the image information contained in it being ableto be selected flexibly in dependence on the specific taking situation.The actual taking image and the additional image can optionally bepresented in the optical viewfinder simultaneously, alternatively to oneanother, alternately in time or alternately with a time overlap.

The electronic display is in particular made for the reproduction ofmotion pictures or of still pictures which supplement the actual takenimage presented in the viewfinder. Those motion pictures can bereproduced at the display which are particularly substantially recordedsimultaneously in time, i.e. synchronously, or with a time lag caused bythe electronic sensor system, by means of the taking sensor. The takenimage presented in the viewfinder via the optical receiving system andthe taken image of the taking sensor reproduced by the display canthereby complement one another in time so that the taken imageobservable in the viewfinder does not flicker.

Since the viewfinder is made as an optical viewfinder, a high imagequality is ensured without the known technical limitations of anelectronic monitor image. The optical viewfinder can moreover beconfigured such that the image section imaged by the optical receivingsystem in the direction of the viewfinder and observable there is largerthan the image section of the taken image actually taken by the takingsensor so that the cameraman can also observe the environment of theactually taken image section.

Although an optical viewfinder is provided, it can be used by means ofthe electronic display and the optical vision mixer to view alreadytaken and stored motion picture sequences. The optical viewfinder cantherefore be used for the monitoring of a motion picture sequencealready recorded at an earlier point in time. Stored motion picturesequences can even be superimposed on the actual taken image during anew take, for example as a reference for the camera work.

Alternatively, the reproduction of different brightness rangecharacteristics, sharpness range characteristics or distance rangecharacteristics (in the form of a “depth card”) can be superimposed onthe actual taken image and offer the cameraman additional support duringthe take. It is furthermore possible to present image format marks oralphanumeric information in the viewfinder by means of the electronicdisplay and the optical vision mixer.

A particular advantage results from the use of a rotating mirroraperture as a beam splitter in the receiving beam path. In this case,the rotation of the mirror aperture necessarily results in anintermittent masking of the incident light on the taking sensor. Withthe camera in accordance with the invention, these masking timeintervals can be reduced with respect to those time intervals in whichthe incident light is deflected in the direction of the viewfinder. Theflickering in the viewfinder caused hereby can namely be balanced inthat the taken image recorded by the sensor is introduced into theviewfinder beam path via the electronic display and the optical visionmixer.

The camera explained is preferably made as a digital electronic motionpicture camera with a digitizing device connected downstream of thetaking sensor.

The invention also relates to the use of an optical vision mixer for thepresentation of a taken image imaged by an optical receiving system andof an additional image reproduced by an electronic display in an opticalviewfinder of an electronic motion picture camera.

The invention furthermore relates to a method for the presentation of ataken image and of an additional image in an optical viewfinder of anelectronic motion picture camera, with an optical receiving systemimaging the taken image along a taking beam bath on a taking sensor andpresenting it along a viewfinder beam path in a view finder, with anelectronic display reproducing the additional image and with an opticalvision mixer directing the taken image imaged by the optical receivingsystem and the additional image reproduced by the electronic display inthe direction of the viewfinder such that the taken image, or theadditional image, or the taken image and the additional image as auniform image, can be observed in the viewfinder.

Further embodiments of the invention are recited in the dependentclaims. The invention will be described in the following purely by wayof example with reference to the drawings, with similar elements beingcharacterized by the same reference numerals.

FIGS. 1 to 8 show different embodiments of an electronic motion picturecamera.

FIG. 1 shows a first embodiment of an electronic motion picture camera.It has an optical receiving system 11 which images the motion picture tobe recorded along a receiving beam path 13. The light incident along thereceiving beam path 13 is alternately transmitted in the direction of ataking beam path 19 or deflected in the direction of a viewfinder beampath 21 by means of a mirror aperture 15 which serves as a beam splitterand which can be driven to make a rotational movement by a drive unit17. For this purpose, the mirror aperture 15 has a transmission region23 and a mirror-coated masking region 25.

A taken image detected by the optical receiving system 11 is thusalternately imaged along the taking beam path 19 on an optoelectronictaking sensor 27 and deflected along the viewfinder beam path 21 to bepresented in an optical viewfinder 29. The taking sensor 27 is imaged,for example, by a CCD or CMOS image converter and it has a signal output31 to output a received signal.

A matt glass screen 33 is arranged in the viewfinder beam path 21 andthe taken image detected by the optical receiving system 11 is imaged onit, provided the masking region 25 of the mirror aperture 15 is locatedin the receiving beam path 13. A real image thereby arises on the mattglass screen 33 which the cameraman can observe by means of theviewfinder 29.

An optical vision mixer 35 is furthermore arranged in the viewfinderbeam path 21 and, on the one hand, permits the viewing of the matt glassscreen 33 through the viewfinder 29 and, on the other hand, presents anadditional image reproduced by an electronic display 37 in theviewfinder 29. The additional image of the electronic display 37 istherefore superimposed on the matt glass screen image by means of theoptical vision mixer 35, with the two superimposed images appearing tothe viewer as one single image in the viewfinder 29 with a correspondingmatching of the two optical branches. For this purpose, the display 37and the matt glass screen 33 are arranged in the same object plane orfocus position of the viewfinder 29.

The optical vision mixer 35 is formed, for example, by a partlytransmitting mirror. The electronic display 37 is formed, for example,by a liquid crystal monitor, a TFT (thin film transistor) monitor or atube monitor (CRT, cathode ray tube). It has a signal input 39 via whichthe additional image or corresponding image signals can be supplied.

The use of an optical viewfinder 29 in conjunction with a matt glassscreen 33 ensures a high quality of the viewfinder image. Despite theuse of an optical viewfinder system, an additional image can also bedisplayed to the cameraman in the viewfinder 29 by means of the display37 and the vision mixer 35 in order hereby to support the take in avaried and flexible manner.

It is in particular possible for motion pictures or still pictures to bereproduced on the electronic display 37 which supplement the taken imageintermittently imaged on the matt glass screen 33 in time such that aflickering of the imaged taken image possibly caused by the rotation ofthe mirror aperture 15 is avoided. The electronic display 37 and theoptical vision mixer 35 can also be used to display a motion picturesequence just taken in the viewfinder 29 for control purposes.Alternatively or additionally, any other image information can bereflected into the viewfinder beam path 21 by means of the display 37and the vision mixer 35.

A further advantage of this camera consists of the fact that an imagecan be seen in the viewfinder 29 on the preparations of a take, whilethe mirror aperture 15 is still standing and the transmission region 23is located in the receiving beam path 13: the taking sensor 27 candeliver a received signal during the taking preparations which is used,for example, for test and reference purposes. At the same time, an imageobservation is possible in the viewfinder 29 despite the mirror aperture15 standing in that the received signal of the taking sensor 27 issupplied via the signal input 39 to the electronic display 37 and isdisplayed by this in the viewfinder 29 via the optical vision mixer 35.

The camera preferably has an adjustment device by which the reproductionof the additional image of the electronic display 37 can be adjustedrelative to the taken image imaged on the matt glass screen 33. Thesize, the position, the alignment or other geometrical properties of theadditional image can, for example, be adapted by such an adjustment inorder to achieve an overlap of identical geometry with the taken imagein the viewfinder 29. This adjustment preferably takes place in anelectronic manner.

It is naturally also possible—in deviation from the representation inaccordance with FIG. 1—for the matt glass screen 33, the optical visionmixer 35 and the viewfinder 29 to be arranged in an L shape so that thevision mixer 35 deflects the taken image imaged on the matt glass screen33 in the direction of the sensor 29 in the direction of the viewfinder29, whereas the additional image of the electronic display 37 isreproduced, for example, in a straight line by the vision mixer 35.

The use of the matt glass screen 33 is not absolutely necessary.Instead, the optical receiving system 11 can generated a virtual imagein the viewfinder beam path 21 which can be viewed together with theadditional image of the display 37 in the viewfinder 29.

Basically, a beam splitter which continuously splits the incident lightcurrent can also be provided instead of the mirror aperture 15.

FIG. 2 shows a further development of the embodiment in accordance withFIG. 1. In this, a signal processing device 41 is provided which isconnected downstream of the taking sensor 27. This prepares the receivedsignal of the taking sensor 27, for example by amplification andpreferably by additional digitizing. The prepared signal is output as adesired signal at the signal output 31, on the one hand, and istransmitted to the electronic display 37, on the other hand.

The electronic display 37 can thus reproduce the current received signalof the taking sensor 27 in real time as an additional image. In theoptical vision mixer 35, the taken image recorded by the taking sensor27 is thereby superimposed on or supplements in time that taken imagewhich is imaged on the matt glass screen 33 by the optical receivingsystem 11 via the rotating mirror aperture 15. The taken imageobservable in the viewfinder 29 thus appears particularly calm, withoutany irritating flickering.

A control device 43 is optionally provided which synchronizes the driveunit 17 of the mirror aperture 15, the taking sensor 27 and theelectronic display 37 such that the taken image imaged on the matt glassscreen 33 by the optical receiving system 11 via the mirror aperture 15and the received signal 37 of the taking sensor 27 reproduced by theelectronic display 37 can be observed substantially alternately, i.e.precisely alternately or with a time overlap, in the viewfinder 29.

The control device 43 shown in FIG. 2 can also control the drive unit 17of the mirror aperture 15 such that the optical receiving system 11 onlyimages the taken image on the taking sensor 27 during an image sequenceto be recorded. In other words, the mirror aperture 15 is temporarilybrought to a standstill so that the transmission region 23 is located inthe received beam path 13. Since the taken image is thus no longerimaged on the matt glass screen 33, the control device 43 causes thedisplay 37 to reproduce the current received signal of the taking sensor27 as an additional image during the whole image sequence. Theviewfinder 29 thus serves as a purely electronic viewfinder. This is ofparticular advantage under poor light conditions, since the totalreceived light can be completely directed to the taking sensor 27.

FIG. 3 shows a further development in which an image memory device 45 isconnected downstream of the taking sensor 27 and of a signal processingdevice 41. This delivers the prepared received signal of the takingsensor 27 to a signal output 31. A further signal output is connected toan input of the electronic display 37. Motion picture data or stillpicture data, which were recorded by the taking sensor 27 at an earlierpoint in time and stored in the image memory device 45, can thus bereproduced at the electronic display 37 and thus be observed in theoptical viewfinder 29. The image memory device 45 thereby permits theviewing of a previously taken motion picture sequence in the viewfinder29 without an additional image monitor being required for this purpose.

A particular advantage of the embodiment in accordance with FIG. 3consists of the fact that a motion picture sequence previously recordedby means of the taking sensor 27 can be superimposed on the taken imageimaged on the matt glass screen 33 during a new take, for example toprovide the cameraman with a reference for the camera work.

Alternatively or additionally, the electronic display 37 or a databuffer connected thereto can have a signal input 39 to which an externalmemory device 47 can be connected to supply motion picture data or stillpicture data to the electronic display 37 which should be reproduced asan additional image in the viewfinder 29 by means of the optical visionmixer 35. It is in particular possible by the connection of an externalmemory device 47 to reproduce picture elements at the electronic display37 which were generated or processed by computer and which should beinserted in the post-processing of the take. Since these pictureelements are already made visible to the cameraman during the take, hecan take the interaction of the real scene with the virtual pictureelements into account. The camera work is hereby substantiallyfacilitated and it is avoided that a recorded motion picture sequencesubsequently proves to be unsuitable for the desired post-processing.

The explained fading of an additional motion picture sequence into theoptical viewfinder 29 is therefore particularly advantageous for theso-called compositing, that is for the recording of motifs in front of ablue background (blue screen) for the subsequent superimposition of aplurality of different motifs in the post-processing. If, for example,the shooting of a real actor in front of a blue screen should later besuperimposed with a representation of a further figure generatedartificially or by a technical trick (e.g. an alien or the like), theartificially generated representation can already be faded into theoptical viewfinder 29 for the cameraman by means of the electronicdisplay 37 during the shooting of the real actor in front of the bluescreen. The cameraman can thus simultaneously observe the real take andthe additionally faded-in representation of the technical trick motifand can influence the camera work accordingly so that it is ensured thatthe final superimposition of the real scene and of the artificial sceneis possible in the post-processing without problem.

FIG. 4 shows a modification of the embodiment in accordance with FIG. 3.In this, an evaluation and control device 49 is connected at the inputside to a signal processing device 41 connected downstream of the takingsensor 27. At the output side, the evaluation and control device 49 isconnected to an image memory device 45 which is connected to theelectronic display 37.

The evaluation and control device 49 is configured such that it controlsthe time of the reproduction of a motion picture sequence stored in theimage memory device 45 on the electronic display 37 in dependence on thecamera movement. In a simple case, the motion picture sequence isreproduced as soon as the evaluation and control device 49 detects thestart of the camera movement or of a recording by means of the takingsensor 27. The evaluation and control device 49 can also be configuredsuch that it evaluates the current received signal of the taking sensor27 with respect to an object movement inside the taken image andcontrols the reproduction frequency with which motion picture data orstill picture data stored in the image memory device 45 are reproducedat the electronic display 37 in dependence on this.

As explained in connection with FIG. 3, a previously recorded motionpicture sequence can, for example, be stored in the image memory device45 which serves as a reference for the camera work or the image datastored in the image memory device 45 corresponds to virtual pictureelements which should be inserted into the post-processing of the take.The evaluation and control device 49 can control the replay of thesestored image data (start point and end point, run speed) in dependenceon the camera movement and/or on the received signal of the takingsensor 27 in order to ensure a synchronization of the stored event withthe real take.

The image data to be inserted via the electronic display 37 can alsoalternatively come from an external memory device in the embodiment inaccordance with FIG. 4. In this case, the additional image is suppliedto the camera via a signal input 39, with the image memory device 45being able to serve as a data buffer.

FIG. 5 shows an embodiment in which the display 37 is connected at theinput side to an image generator 51 which, for example, generates imagearea marks, image format markings, other graphical information oralphanumeric information as an additional image which should bereproduced at the display 37.

For example, a frame can be superimposed on the taken image imaged onthe matt glass screen 33 by means of the image generator 51, the display37 and the vision mixer 35 which marks the image section of theassociated image format in dependence on the purpose of the recording(cinema or television). A permanent marking of the matt glass screen 33or a replacement of differently marked matt glass screens 33 is thus notnecessary. The image information generated by the image generator 51can, for example, also be an alphanumeric identification of the setaperture or of the set depth of field range.

The image generator 51 is optionally connected at the input side to anevaluation and control device 49 which is in turn connected at the inputside to the taking sensor 27 or to an associated signal processingdevice. The evaluation and control device 49 evaluates the receivedsignal of the taking sensor 27 with respect to pre-determined brightnessor sharpness values and causes the image generator to generatecorresponding brightness range mark or sharpness range marks which arereproduced at the electronic display 37. An electronic image speciallyprepared from the sensor image is thus superimposed on the taken imageobservable at the matt glass screen 33 in order to draw the attention ofthe cameraman to areas with a specific brightness or sharpness(modulation frequency). These areas can be marked by the image generator51, for example by hatching.

In accordance with an advantageous embodiment, the evaluation andcontrol device 49 can respectively compare the received signal of thetaking sensor 27 for the individual picture elements of the taken image,for example by means of a comparator, with an upper brightness thresholdvalue or with a lower brightness threshold value or with both the saidbrightness threshold values. In this case, the evaluation and controldevice 49 can calculate or determine at least one brightness range ofthe taken image within which the respective received signal exceeds theupper brightness threshold value or does not reach the lower brightnessthreshold value for the picture elements of the taken image or at leastfor a predominant proportion of the picture elements. The imagegenerator 51 generates corresponding brightness range marks, for examplethe already named hatching, on the basis of the brightness ranges thusdetermined. These brightness range marks are therefore generated at thedisplay 37 and are thus visible in the optical viewfinder 29 as warningsigns superimposed with respect to the taken image.

The generation and display of such brightness range marks isparticularly of importance with motion picture cameras having anoptoelectronic taking sensor, since this generally has a lowerbrightness dynamic range than conventional photochemical film material,with the threshold values for critical upper and lower brightness valuesbeing sensor-dependent. It is therefore advantageous if image regionscan be displayed to the cameraman in which the brightness values of themotif to be recorded could prove to be problematic so that the cameramancan take account of the explained warning signs or image region marksduring the camera work. This function is important for a test run, onthe one hand, in order optionally to be able to alter the set (forexample in that a coffee pot reflecting the sunlight is moved into theshade). On the other hand, this function is important for the actual,final take, since the cameraman thus has a control possibility that noproblematic brightness areas are also actually recorded during the take.If, in contrast, it were only to be found after the take, namely on theviewing of the recorded film scene, that problematic brightness valuesor brightness regions had been recorded, a subsequent repeat recordingof the film scene would mostly be very costly or even impossible, sincethe set would have to be recreated again.

It is important that the cameraman himself—and not any other person—canobserve the explained brightness range marks, and indeed in the opticalviewfinder. The cameraman can therefore himself keep control of thebrightness modulation of the taken image and, optionally, influence thecamera work accordingly, and he does not have to dispense with the useof the customary optical viewfinder 29 to do so. It is also importantthat not only a simple warning signal is transmitted to the cameraman,but rather that it is specifically indicated in which picture region theerror occurs.

The function of the display of image region marks and in particular ofbrightness range marks is also of importance for the compositing alreadymentioned in connection with FIG. 3, that is for the recording of motifsin front of a blue screen. It is also namely important here that thesplit of the taken image into different color regions or brightnessregions—that is the quality of the segmentation—can be observed andcontrolled. It can, for example, prove to be problematic if a personwearing a green item of clothing, or even a blue item of clothing, isfilmed in front of the blue screen. Potentially critical image regionscan be indicated to the cameraman by the explained comparison of thereceived signals with corresponding threshold values.

It is of advantage for the named application of the compositing for thereceived signals of the taking sensor 27 to be compared with differentthreshold values for the different picture elements with respect to eachof the colors red, green and blue, since the received signals of thecolor blue, for example, are more critical than the received signals ofthe color green. A comparison with a brightness threshold value alsodoes not necessarily have to be carried out for each color. For example,such a comparison is not absolutely necessary for the color red withrespect to the compositing.

FIG. 6 shows a modification of the embodiment in accordance with FIG. 5in which a range finding device 53 is additionally provided. It is, forexample, formed by an infrared sensor or a laser range finder. The rangefinder device 53 is connected to an evaluation and control device 49which is connected to the taking sensor 27 at the input side and to animage generator 51 for the electronic display 37 at the output side.

The range finder device 53 can measure the distance of the camera froman object within the recorded object space. The corresponding measuredsignal can be evaluated by the evaluation and control device 49 fordifferent distance regions of the object space and thus of the takenimage recorded by the taking sensor 27. Depending on this evaluation,the evaluation and control device 49 causes the image generator 51 togenerate corresponding distance region marks which are reproduced by theelectronic display 37 and are thus superimposed on the matt glass image.

In this manner, a type of “depth map” is made available to the cameramanin the viewfinder 29 which permits a fast identification of the objectspacings and/or of the sharpness plane—for example by different coloring(false color representation), by hatching or by presentation ofdifferent distance ranges with different brightness. In particular theadjustment of a desired depth of field region is hereby facilitated. Aplurality of range finding devices 53 can naturally be provided todetect the different distance regions of the taken image fast and withhigh resolution.

FIG. 7 shows an embodiment with a photodetector 55 which measures thebrightness of the taken image imaged on the matt glass screen 33 by theoptical receiving system 11. The photodetector 55 is connected to abrightness regulation device 57 which regulates the brightness of thereproduction of the additional image at the electronic display 37 independence on the measured brightness of the matt glass screen image.The brightness regulation device 57 can be configured, for example, suchthat the taken image imaged by the optical receiving system 11 and theadditional image of the electronic display 37 superimposed thereon areseen by the viewer with the same brightness or with a brightnessdifference which remains the same.

Instead of the shown brightness regulation device 57 with aphotodetector 55, a simple brightness control device can also beprovided which is connected to the electronic display 37 in order to beable to set the brightness of the reproduction of the additional imageto a desired value.

It is preferred for the embodiment in accordance with FIG. 1 for theoptical vision mixer 35—for example in the form of a partiallytransmitting mirror—to be able to direct both the taken image imaged onthe matt glass screen 33 by the optical receiving system 11 and theadditional image of the electronic display 37 in the direction of theviewfinder 29 simultaneously.

FIG. 8 shows an alternative embodiment to this in which the opticalvision mixer 35 selectively directs the taken image imaged by theoptical receiving system 11 or the additional image of the electricaldisplay 37, or simultaneously the taken image and the additional image,in the direction of the viewfinder 29. For this purpose, the visionmixer 35 can have a fully transmitting section 59, a fully reflectivesection 61 and a partly reflective/partly transmitting section 63 whichare selectively introduced into the viewfinder beam path 21. The threesections 59, 61, 63 can, for example, be arranged at a vision mixercarousel by whose rotation the desired section is brought into theviewfinder beam path 21.

Alternatively to such a carousel, the vision mixer 35 can also permit acontinuous variation of the splitter ratio so that the relative portionsof the two presentations, that is of the taken image reproduced at thematt glass screen 33 and of the additional image reproduced by thedisplay 37, can be offset with respect to one another for the viewer.The vision mixer 35 can, for example, have a liquid crystal mirror withcontrollable transmission so that a larger portion of the taken image ora larger portion of the additional image is directed in the direction ofthe viewfinder 29 in dependence on the arrangement of the liquidcrystals.

It must finally be noted that the embodiments explained in connectionwith FIGS. 1 to 8 can be combined with one another in any form in orderto use the vision mixer 35 and the display 37 with even greater variety.

REFERENCE NUMERAL LIST

-   11 optical receiving system-   13 receiving beam path-   15 mirror aperture-   17 drive unit-   19 taking beam path-   21 viewfinder beam path-   23 transmission region-   25 masked region-   27 taking sensor-   29 viewfinder-   31 signal output-   33 matt glass screen-   35 optical vision mixer-   37 electronic display-   39 signal input-   41 signal processing device-   43 control device-   45 image memory device-   47 external memory device-   49 evaluation and control device-   51 image generator-   53 range finder device-   55 photodetector-   57 brightness regulation device-   59 fully transmitting section-   61 fully reflective section-   63 partly reflective/partly transmitting section

1. An electronic motion picture camera, having an optical receivingsystem (11) and a rotating mirror aperture (15) which directs a takenimage imaged by the optical receiving system (11) alternately along ataking beam path (19) in the direction of an optoelectronic takingsensor (27) and along a viewfinder beam path (21) in the direction of anoptical viewfinder (29), wherein a matt glass screen (33) is arranged inthe viewfinder beam path (21) such that the taken image directed alongthe viewfinder beam path (21) is imaged on the matt glass screen (33),wherein the camera has a signal processing device (41) which isconnected to the taking sensor (27) and which processes a signalproduced by the taking sensor (27), wherein the camera has an electronicdisplay (37) which is connected to the signal processing device (41) andwhich reproduces the processed signal as an additional imagesubstantially at the same time when the taking sensor (27) produces thesignal, wherein an optical vision mixer (35) is arranged in theviewfinder beam path (21) between the matt glass screen (33) and theoptical viewfinder (29), wherein the optical vision mixer (35) isadapted to direct the taken image imaged on the matt glass screen (33)and the additional image reproduced by the electronic display (37) inthe direction of the viewfinder (29), and wherein the camera has acontrol device (43) which controls the rotating mirror aperture (15),the taking sensor (27) and the electronic display (37) such that thetaken image imaged on the matt glass screen (33) and the additionalimage reproduced by the electronic display (37) are shown substantiallyalternately in the viewfinder (29).
 2. A camera in accordance with claim1, wherein the camera has an evaluation and control device (49) which isconnected to the electronic display (37), with the reproduction time orthe reproduction frequency of stored or read-in motion picture data orstill picture data at the electronic display (37) being able to becontrolled by means of the control and evaluation device (49) independence on the camera movement.
 3. A camera in accordance with claim1, wherein the electronic display (37) has a liquid crystal monitor, aTFT monitor or a CRT monitor.
 4. A camera in accordance with claim 1,wherein the image section of the taken image imaged by the opticalreceiving system (11) in the viewfinder (29) and observable there islarger than the image section of the taken image actually taken by thetaking sensor (27).
 5. A camera in accordance with claim 1, wherein theelectronic display (37) and the matt glass screen (33) are arranged inthe same object plane of the viewfinder (29).
 6. A camera in accordancewith claim 1, wherein the camera is made as a digital electronic motionpicture camera with a digitizing device (41) connected downstream of thetaking sensor (27).
 7. A method for presenting a taken image and anadditional image in an optical viewfinder (29) of an electronic motionpicture camera, comprising the steps of: imaging the taken image along areceiving beam path (13) by means of an optical receiving system (11);directing the taken image alternately along a taking beam path (19) inthe direction of a taking sensor (27) and along a viewfinder beam path(21) in the direction of a viewfinder (29) by means of a rotating mirroraperture (15) arranged in the receiving beam path (13); imaging thetaken image directed along the viewfinder beam path (21) on a matt glassscreen (33); processing a signal produced by the taking sensor (27);reproducing the processed signal as the additional image by means of anelectronic display (37) substantially at the same time when the takingsensor (27) produces the signal; directing the taken image imaged on thematt glass screen (33) and the additional image reproduced by theelectronic display (37) in the direction of the viewfinder (29); andcontrolling the rotating mirror aperture (15), the taking sensor (27)and the electronic display (37) such that the taken image imaged on thematt glass screen (33) and the additional image reproduced by theelectronic display (37) are shown substantially alternately in theviewfinder (29).
 8. An electronic motion picture camera, having anoptical receiving system (11) and a beam splitter (15) which splits areceiving beam path (13) into a taking beam path (19) leading to anoptoelectronic taking sensor (27) and a viewfinder beam path (21)leading to an optical viewfinder (29), wherein the camera has an imagememory device (45) which stores motion picture data or still picturedata produced by the taking sensor (27), wherein the camera has anelectronic display (37) which is connected to the image memory device(45) and which reproduces the stored motion picture data or stillpicture data as an additional image, and wherein an optical vision mixer(35) is arranged in the viewfinder beam path (21) which directs a takenimage imaged along the viewfinder beam path (21) by the opticalreceiving system (11) and the additional image reproduced by theelectronic display (37) in the direction of the viewfinder (29) suchthat the stored motion picture data or still picture data aresuperimposed on the taken image in the viewfinder (29) while a signal ofthe taking sensor (27) representing the taken image is delivered to asignal output (31) of the camera.
 9. A camera in accordance with claim8, wherein the electronic display (37) has a signal input (39), andwherein the electronic display (37) is adapted to reproduce motionpicture data or still picture data read in via the signal input (39).10. A camera in accordance with claim 8, wherein the optical visionmixer (35) simultaneously directs the taken image imaged by the opticalreceiving system (11) and the additional image reproduced by theelectronic display (37) in the direction of the viewfinder (29).
 11. Acamera in accordance with claim 8, wherein the optical vision mixer (35)has a partly transmitting mirror.
 12. A camera in accordance with claim8, wherein the beam splitter has a rotating mirror aperture (15) whichalternately directs the taken image imaged by the optical receivingsystem (11) in the direction of the taking sensor (27) and in thedirection of the viewfinder (29).
 13. A camera in accordance with claim8, wherein a matt glass screen (33) is arranged in the viewfinder beampath (21), wherein the optical vision mixer (35) is arranged between thematt glass screen (33) and the viewfinder (29) and wherein the opticalreceiving system (11) images the taken image on the matt glass screen(33).
 14. A method for presenting a taken image and an additional imagein an optical viewfinder (29) of an electronic motion picture camera,comprising the steps of: imaging the taken image along a receiving beampath (13) by means of an optical receiving system (11); splitting thereceiving beam path (13) into a taking beam path (19) leading to ataking sensor (27) and a viewfinder beam path (21) leading to theoptical viewfinder (29); producing motion picture data or still picturedata by means of the taking sensor (27); storing the motion picture dataor still picture data in an image memory device (45); reproducing thestored motion picture data or still picture data as the additional imageby means of an electronic display (37); and directing the taken imageimaged along the viewfinder beam path (21) and the additional imagereproduced by the electronic display (37) in the direction of theviewfinder (29) such that the stored motion picture data or stillpicture data are superimposed on the taken image in the viewfinder (29)while a signal of the taking sensor (27) representing the taken image isdelivered to a signal output (31) of the camera.
 15. A method inaccordance with claim 14, wherein the step of splitting the receivingbeam path (13) comprises alternately directing the taken image in thedirection of the taking beam path (19) and the viewfinder beam path (21)by means of a rotating mirror aperture (15).
 16. A method in accordancewith claim 14, wherein the step of splitting the receiving beam path(13) comprises imaging the taken image on a matt glass screen (33)arranged in the viewfinder beam path (21).
 17. An electronic motionpicture camera, having an optical receiving system (11) and a beamsplitter (15) which splits a receiving beam path (13) into a taking beampath (19) leading to an optoelectronic taking sensor (27) and aviewfinder beam path (21) leading to an optical viewfinder (29), whereinthe camera has an electronic display (37) which has a signal input (39)and which reproduces motion picture data or still picture data suppliedvia the signal input (39) as an additional image, and wherein an opticalvision mixer (35) is arranged in the viewfinder beam path (21) whichdirects a taken image imaged along the taking beam path (19) by theoptical receiving system (11) and the additional image reproduced by theelectronic display (37) in the direction of the viewfinder (29) suchthat the motion picture data or still picture data supplied via thesignal input (39) are superimposed on the taken image in the viewfinder(29) while a signal of the taking sensor (27) representing the takenimage is delivered to a signal output (31) of the camera.
 18. A camerain accordance with claim 17, wherein the electronic display (37) isconnected to an image memory device (45) connected to the taking sensor(27), and wherein the electronic display (37) is adapted to reproducemotion picture data or still picture data of the taking sensor (27)stored in the image memory device (45) as an additional image.
 19. Acamera in accordance with claim 17, wherein the beam splitter has arotating mirror aperture (15) which alternately directs the taken imageimaged by the optical receiving system (11) in the direction of thetaking sensor (27) and in the direction of the viewfinder (29).
 20. Acamera in accordance with claim 17, wherein a matt glass screen (33) isarranged in the viewfinder beam path (21), wherein the optical visionmixer (35) is arranged between the matt glass screen (33) and theviewfinder (29) and wherein the optical receiving system (11) images thetaken image on the matt glass screen (33).
 21. A method for presenting ataken image and an additional image in an optical viewfinder (29) of anelectronic motion picture camera, comprising the steps of: imaging thetaken image along a receiving beam path (13) by means of an opticalreceiving system (11); splitting the receiving beam path (13) into ataking beam path (19) leading to a taking sensor (27) and a viewfinderbeam path (21) leading to the optical viewfinder (29); supplying motionpicture data or still picture data from an external memory device (47)to the electronic display (37); reproducing the motion picture data orstill picture data as the additional image by means of an electronicdisplay (37); and directing the taken image imaged along the viewfinderbeam path (21) and the additional image reproduced by the electronicdisplay (37) in the direction of a viewfinder (29) such that the motionpicture data or still picture data supplied from the external memorydevice are superimposed on the taken image in the viewfinder (29) whilea signal of the taking sensor (27) representing the taken image isdelivered to a signal output (31) of the camera.
 22. A method inaccordance with claim 21, wherein the step of splitting the receivingbeam path (13) comprises alternately directing the taken image in thedirection of the taking beam path (19) and the viewfinder beam path (21)by means of a rotating mirror aperture (15).
 23. A method in accordancewith claim 21, wherein the step of splitting the receiving beam path(13) comprises imaging the taken image on a matt glass screen (33)arranged in the viewfinder beam path (21).
 24. An electronic motionpicture camera, having an optical receiving system (11) which images ataken image along a receiving beam path (13), and a mirror aperture (15)which has a transmission region (23) and a mirror-coated masking region(25), wherein the mirror aperture (15) is adapted to direct the takenimage imaged by the optical receiving system (11) selectively along ataking beam path (19) in the direction of an optoelectronic takingsensor (27) if the transmission region (23) is located in the receivingbeam path (13), or along a viewfinder beam path (21) in the direction ofan optical viewfinder (29) if the mirror-coated masking region (25) islocated in the receiving beam path (13), wherein the camera has a signalprocessing device (41) which is connected to the taking sensor (27) andwhich processes a signal produced by the taking sensor (27), wherein thecamera has an electronic display (37) which is connected to the signalprocessing device (41) and which reproduces the processed signal as anadditional image substantially at the same time when the taking sensor(27) produces the signal, wherein an optical vision mixer (35) isarranged in the viewfinder beam path (21) which is adapted to direct thetaken image imaged along the viewfinder beam path (21) by the opticalreceiving system (11) or the additional image reproduced by theelectronic display (37) in the direction of the viewfinder (29), andwherein the camera has a control device (43) which controls the mirroraperture (15) and the electronic display (37) such that during asequence of a plurality of successive motion pictures, the transmissionregion (23) of the mirror aperture (15) is moved into the receiving beampath (13), wherein the optical receiving system (11) continuously imagesthe taken image along the taking beam path (19) on the taking sensor(27), and the electronic display (37) continuously reproduces theprocessed signal as the additional image.
 25. A method for presenting ataken image in an optical viewfinder (29) of an electronic motionpicture camera, comprising the steps of: imaging the taken image along areceiving beam path (13) by means of an optical receiving system (11);arranging a mirror aperture (15) in the receiving beam path (13),wherein the mirror aperture (15) has a transmission region (23) and amirror-coated masking region (25); selectively moving the transmissionregion (23) of the mirror aperture (15) into the receiving beam path(13), thereby directing the taken image imaged by the optical receivingsystem (11) along a taking beam path (19) in the direction of anoptoelectronic taking sensor (27), or moving the mirror-coated maskingregion (25) of the mirror aperture (15) into the receiving beam path(13), thereby directing the taken image imaged by the optical receivingsystem (11) along a viewfinder beam path (21) in the direction of anoptical viewfinder (29); processing a signal produced by the takingsensor (27); reproducing the processed signal as an additional image bymeans of an electronic display (37) substantially at the same time whenthe taking sensor (27) produces the signal; directing the taken imageimaged along the viewfinder beam path (21) or the additional imagereproduced by the electronic display (37) in the direction of theviewfinder (29); and controlling the mirror aperture (15) and theelectronic display (37) such that during a sequence of a plurality ofsuccessive motion pictures, the transmission region (23) of the mirroraperture (15) is located in the receiving beam path (13), wherein theoptical receiving system (11) continuously images the taken image alongthe taking beam path (19) on the taking sensor (27), and the electronicdisplay (37) continuously reproduces the processed signal as theadditional image.